[Multiple cerebral infarctions in the deep perforator regions in a case of idiopathic hypereosinophilic syndrome].

A 61-year-old man was admitted to our hospital due to cerebral infarction in the pons and the right putamen. On admission (day 3 from symptom onset), laboratory testing showed a white blood cell count of 13,100/μl with hypereosinophilia of 3,734/μl. As deep vein thrombosis was detected on contrast-enhanced CT, we started anticoagulation therapy. There were no cardio-embolic sources, including right-to-left shunt, but eosinophil infiltration was found in biopsy specimens of the gastric mucosa. These findings allowed us to diagnose multiple perforator infarction due to idiopathic hypereosinophilic syndrome (idiopathic HES). After the administration of oral prednisolone was started on day 10, his hypereosinophilia rapidly improved, and no recurrence of deep perforator infarction occurred other than a symptomatic infarction in the left putamen at day 19. There are a few reports of idiopathic HES with multiple infarctions developing in deep perforator regions. The current case suggests that idiopathic HES could cause multiple cerebral infarction restricted to deep perforator areas.